Interesting that the authors are from Cadence. I didn't know they were big players in the STA arena. I know they have an "Encounter" timing system, but I'm not familiar with how advanced or accepted it is.
The article reinforces my view that statistical STA is "not ready for PrimeTime". That pun is not a slam against Synopsys! I mean that there needs to be a lot more support from the foundries and understanding by the design community before there's much adoption of SSTA for production chip timing.
Another good article, which was just published and is written by Extreme DA's founder, is Statistical static timing analysis: A view from the future.